I am new to this site and have tried to locate a thread on what diff oil to use in my rear diff w/e-locker? Also what to use in the front Diff w/4x4.The manual only mentions what oil to use with LSD and W/out LSD and dealer said I should half to drain it out and smell it if it has that diff oil smell or not. If no smell it would be 75w90 with synthetic. and if not a 90w. But he said I should bring it in and have them service it. He also said for $400 they could perform my 15,000 mile service and they will do the front and rear diffs and check everything else. I think this is BS. Anyone out there with a few answers would be greatly appreciated. Thanx

damn! $400.00 for the 15k service? should just be an oil change and lube. 30k is the one for all fluid changes and plugs...just did mine. used royal purple 75w-90for the diffs and transfer case. denso iridium spark plugs, all new crush washers & gaskets. i was quoted $500 for the 30k service at my dealer. did it myself with the most premium stuff i could find for less than $200.

don't know where to get Redline at...maybe here on the net. O'reiley's carries the royal purple. dont think high dollar oil is neccesary, but i'm a top shelf kinda guy when it comes to my truck.